[Antigenicity analysis of nucleocapsid proteins of 3 human coronaviruses SARS-CoV, 229E and OC43 with their monoclonal antibodies].

Qiu, Li-wen; Wang, Ya-di; Liao, Zhi-yong; Wen, Kun; Che, Xiao-yan

OBJECTIVE To prepare and characterize monoclonal antibodies (mAbs) against the recombinant nucleocapsid (N) protein of 3 human coronaviruses SARS-CoV, 229E and OC43 and study the antigenic relationship between the 3 N proteins. METHODS BALB/c mice were immunized with the recombinant N proteins of SARS-CoV, 229E and OC43 to obtain the mAbs by means of hybridoma. Screening and identification of the mAbs were performed using indirect enzyme-linked immunosorbent assay (ELISA), Western blotting and indirect immunofluorescence assay. Cross-reactivity between the N proteins of the 3 coronaviruses was analyzed with the prepared mAbs. RESULTS The mAbs against the recombinant N proteins of SARS-CoV, 229E and OC43 were obtained, which reacted specifically with the corresponding viral N protein as shown by indirect ELISA, Western blotting and indirect immunofluorescence assay. No cross-reactivity was found between the 3 N proteins. CONCLUSION The prepared mAbs against the recombinant N proteins may provide valuable assistance in studying antigenic relationships of N proteins between the 3 human coronaviruses.